1. Field of the Invention
This invention concerns clutches, and more particularly friction clutches which transmit constant torque levels.
2. Description of the Prior Art
In many clutch designs, the torque level transmissible through the clutch may vary, particularly in electromagnetically actuated clutches, due to such variable factors as line voltage, temperature, friction surface coefficient, duration of duty cycles, etc. These factors will vary the torque which may be developed from such pressure.
Such variations in torque levels can be troublesome in applications where the timing of the development of particular torque level is critical to proper performance of the unit.
While separate torque limiting devices could be used, this would significantly increase the cost of the unit.
Accordingly, it is an object of the present invention to provide such a clutch in which variations in operating conditions do not change the torque transmitted through the clutch.
It is another object of the present invention to provide such a constant torque level which may be set to a predictable level which can be reliably repeated.
It is still another object of the present invention to provide such a clutch without the need for a separate torque limiting assembly.
It is yet another object of the present invention to provide a simple and reliable arrangement for achieving such constant preset torque level transmissible through the clutch.